package com.imageFilters.view;

import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;

public class MulitPointTouchListener implements OnTouchListener { 
    Matrix matrix = new Matrix(); 
    Matrix savedMatrix = new Matrix(); 

    static final int NONE = 0; 
    static final int DRAG = 1; 
    static final int ZOOM = 2; 
    int mode = NONE; 

    PointF start = new PointF(); 
    PointF mid = new PointF(); 
    float oldDist = 1f; 

    public boolean onTouch(View v, MotionEvent event) { 

            ImageView view = (ImageView) v; 

            switch (event.getAction() & MotionEvent.ACTION_MASK) { 
            case MotionEvent.ACTION_DOWN: 

                    matrix.set(view.getImageMatrix()); 
                    savedMatrix.set(matrix); 
                    start.set(event.getX(), event.getY()); 
                    mode = DRAG; 

                   
                    break; 
            case MotionEvent.ACTION_POINTER_DOWN: 
                    oldDist = spacing(event); 
                    if (oldDist > 10f) { 
                            savedMatrix.set(matrix); 
                            midPoint(mid, event); 
                            mode = ZOOM; 
                    } 
                    break; 
            case MotionEvent.ACTION_UP: 
            case MotionEvent.ACTION_POINTER_UP: 
                    mode = NONE; 

                    break; 
            case MotionEvent.ACTION_MOVE: 
                    if (mode == DRAG) { 
                            matrix.set(savedMatrix); 
                            matrix.postTranslate(event.getX() - start.x, event.getY() 
                                            - start.y); 
                    } else if (mode == ZOOM) { 
                            float newDist = spacing(event); 
                            if (newDist > 10f) { 
                                    matrix.set(savedMatrix); 
                                    float scale = newDist / oldDist; 
                                    matrix.postScale(scale, scale, mid.x, mid.y); 
                            } 
                    } 
                    break; 
            } 

            view.setImageMatrix(matrix); 
            return true; 
    } 

    
   
    private float spacing(MotionEvent event) { 
            float x = event.getX(0) - event.getX(1); 
            float y = event.getY(0) - event.getY(1); 
            return FloatMath.sqrt(x * x + y * y); 
    } 

   
    private void midPoint(PointF point, MotionEvent event) { 
            float x = event.getX(0) + event.getX(1); 
            float y = event.getY(0) + event.getY(1); 
            point.set(x / 2, y / 2); 
    } 
} 